PNSPO! Modbus Solution CP1H / CP1L / CJ1 / CJ2 / CS1. Version /18/2009

Transcription

1 PNSPO!! Modbus Solution CP1H / CP1L / CJ1 / CJ2 / CS1 Version /18/2009

2 Section 1. Overview The Omron CP1H and CP1L PLCs offer a built in function called Easy Modbus, that performs a Modbus RTU Master function, allowing the PLC to communicate with devices that use the Modbus RTU protocol, such as inverters, scales, temperature controllers, etc. The CJ1 / CJ2 / CS1 PLCs support Modbus through a Protocol Macro. While the Easy Modbus or Protocol Macro functions are powerful functions, they require the user to develop a ladder program to feed data to and retrieve data from the Easy Modbus or Protocol Macro function. This can be intimidating to a user. This Modbus Solution was developed to provide a pre-written solution to Modbus RTU applications, supporting up to 100 items to read and 100 items to write. An item is an individual data point on a device such as present temperature of node 4, or frequency reference on node 7. The Modbus RTU function codes that are supported are: 01: Read Coil Status 02: Read Input Status 03: Read Holding Registers (1 or 2 registers) 04: Read Input Registers (1 32 coils) 05: Force Single Coil 06: Preset Single Register 0F: Force Multiple Coils (1 32 coils) 10: Preset Multiple Registers (1 or 2 registers) The NS series HMI application that is provided is not necessary for the solution, but is intended to assist in setup and monitoring of the Modbus Solution. Memory Considerations: The Modbus Solution uses ~ 1,500 steps of PLC User Memory for CP1H / CP1L and ~1600 steps for CJ1 / CJ2 / CS1. This represents the following amount for each PLC CPU type. Keep this memory usage in mind when selecting a PLC CPU for an application. PLC Total UM Remaining % Used CP1H-X, XA, Y/ CJ1M-CPU13 21,504 Steps ~ 20,000 steps 7% CP1L-M / CJ1M-CPU12 11,264 Steps ~ 9,700 Steps 14% CP1L-L / CJ1M-CPU11 6,144 Steps ~ 4,600 Steps 25% CS1G-CPU42-H / CJ1G-CPU42-H 11,264 Steps ~ 9,700 Steps 14% CS1G-CPU43-H / CJ1G-CPU43-H 21,504 Steps ~ 20,000 steps 7% CS1G-CPU44-H / CJ1G-CPU44-H 31,744 Steps ~ 30,000 steps 5% Others Negligible Memory Usage

3 Section 2. Hardware Requirements PLC To use the Modbus Solution 1 CP1H or CP1L PLC 1 CP1W-CIF11 or CIF12 RS422/485 serial adapter or 1 CJ1 / CJ2 / CS1 with Serial Communications Unit (SCU41 or SCU31) To use the NS Series HMI application The PLC must have an RS232 port (CP1H or CP1L-M type, or CJ1 / CJ2/ CS1) 1 CP1W-CIF01 for communications to the HMI from CP1H or CP1L 1 NS8 HMI 1 C200H-CN510-EU (or similar) PLC to NS cable Section 3. Setup for CP1L / CP1H The CP1W-CIF11 must be installed in the rightmost option board position. For CPUs with 2 option board positions, do not use the leftmost position. The ladder program was not written for this option board position. For RS-485 communications, set the DIP switches on the back of the CP1W- CIF11 or CIF12 adapter as shown prior to installing in the PLC.

4 The Port that is being used for Modbus communications will need to be configured as shown. Be certain to download the PLC settings to configure the serial port, and make certain that the DIP Switch associated with the port is OFF. This is DIP Switch 4 on CP1L-L, and DIP Switch 5 on CP1L-M and CP1H.

5 Section 3. Setup for CJ1 / CJ2 / CS1 The CJ1 / CJ2 / CS1 configuration for the Modbus Solution requires an SCU31 / SCU41 module. The built in ports on the PLC CPU cannot be used for this function. An SCB (Serial Communications Board) on a CS1 cannot be used for this function. The SCU module must be set for unit #F, and the top communications port is used as shown. Set the 2/4 wire mode for 2 wire (RS485), and the Terminating Resistance switch to ON.

6 The port must be configured through the I/O table of CX Programmer, and setup as shown below. The Protocol Macro must also be downloaded to the SCU module via CX Protocol.

7 Section 4. Data Layout for Modbus RTU data exchange To read and write data from and to a Modbus RTU capable device, the user simply manipulates data in data tables in the PLCs DM (Data Memory) area. The Modbus Solution automatically communicates to the Modbus devices based on the data tables. To read from a Modbus Slave device: The user fills in the Read Data Table as follows. Item 1 is shown, but the data layout is the same for all items. Shaded items are set by the user, non-shaded items are populated by the Modbus Solution. Item 1: D5000 D5009 Item 2: D5010 D5019 Item 100 : D5990 D5999 The PLC program will cycle through the items in order. To mark the last item to read, enter F000 in the Last Item to Read memory location for the last item. Set 0000 for all but the last item. If there are no read items for the application, set D5009 to E000. Address Setting D5000 Modbus Slave Node Number In HEX D5001 Modbus Function Code In HEX D5002 Starting Modbus Address to Read In HEX D5003 Number of Modbus Addresses to Read In HEX, 0 31 for coils, 0 or 1 for registers D5004 First word of Response Data D5005 Second word of Response Data Not used if < 16 coils or 1 register is read D5006 Not used D5007 Not used D5008 Is the Data Valid? FFFF = invalid (ie error), 0000 = valid, F000 = data not yet read (set on powerup) D5009 Last Item to Read? Set to F000 if this is the last item to read Example: To read the present frequency and current for an Omron 3G3JX inverter, the Read Data Tables would be configured as follows: Address Value Notes Address Value Notes D Node 1 D Node 1 D Function code 3 D Function code 3 D Frequency Register D Current Register D Read 1 Register D Read 1 Register D Freq. Returned Here D Current Returned Here D D D Not Used D Not Used D Not Used D Not Used D Data is valid D Data is valid D Not last item D5019 F000 Last Item

8 To write to a Modbus Slave device: The user fills in the Write Data Table as follows. Item 1 is shown, but the data layout is the same for all items. Shaded items are set by the user, non-shaded items are populated by the Modbus Solution. Item 1: D6000 D6009 Item 2: D6010 D6019 Item 100 : D6990 D6999 The PLC program will cycle through the items in the read table, and write data to a Modbus Slave only on Data Change. To mark the last item to write, enter F00x in the Last Item to Write memory location for the last item. Set 000x for all but the last item. To set a particular write item to FFFF after the data is written to the device, set xxxa in the Last Item field. This allows the same value to be written over and over again in the Data register of the Modbus Solution, and the Modbus Solution will correctly detect the changing data = Not Last Write Item, do not detect same value write 000A = Not Last Write Item, detect same value write F000 = Last Write Item, do not detect same value write F00A = Last Write Item, detect same value write. Address Setting D6000 Modbus Slave Node Number In HEX D6001 Modbus Function Code In HEX D6002 Starting Modbus Address to Write In HEX D6003 Number of Modbus Addresses to Write In HEX, 0 31 for coils, 0 or 1 for registers D6004 First word of Write Data D6005 Second word of Write Data Not used if < 16 coils or 1 register is read D6006 Copy of last data sent first write word Used to detect changed data D6007 Copy of last data sent second write word Used to detect changed data D6008 Last Write Successful? FFFF = unsuccessful (ie error), 0000 = valid, F000 = data not yet written (set on powerup) D6009 Last Item to Write / Detect Same Data? 0000, 000A, F000, F00A as explained above

9 Example: To Write a Frequency Reference for Omron 3G3JX inverters at nodes 9 and 12, the Write Data Tables would be configured as follows: Address Value Notes Address Value Notes D Node 9 D C Node 12 D Function code 10 D Function code 10 D F Ref Register D F Ref Register D Write 1 Register D Write 1 Register D = 15.0 hz D C 17C = 38.0 hz D Not used D Not used D Program controlled D Program controlled D Program controlled D Program controlled D Last Write Successful? D Last Write Successful? D A Not last item, detect same write value D6019 F00A Last Item, detect same write value

10 Section 5. Used Memory Areas The following memory areas are used for the Modbus Solution, and cannot be used for other purposes in the PLC: Timers 13, 14, 15 W0 W249 D5000 D6999 Jump / Jump End DF, EF, FF Section 6. Error Logging and Cycle Time Monitoring The Modbus Solution has build in error detection. Each read item and write item has its own status area. For read items, this is the Is the Data Valid field. For write items, this is the Last Write Successful field. Each Read / Write has a 3 retry on timeout setting. The timeout value is set in the PLC port setup for CP1H / CP1L, and in the Protocol macro for CJ1 / CJ2 / CS1. The Modbus Solution has an overall error log. The last 5 errors are logged as follows: (W220 + W221 is the most recent error). Consult the Modbus specification for the slave device to determine the cause and solution to the Modbus error. Address Item Example W220 Record 1 Node Number Function Code 0205 (node 2, function 05) W221 Record 1 DM Area that caused error 1392 (5010 DEC) = D5010 W222 Record 2 Node Number Function Code 0710 (node 7, function 10) W223 Record 2 DM Area that caused error 17A2 (6050 DEC) = D6050 W224 Record 3 Node Number Function Code 0801 (node 8, function 01) W225 Record 3 DM Area that caused error 13CE (5070 DEC) = D5070 W226 Record 4 Node Number Function Code 0A03 (node 10, function 03) W227 Record 4 DM Area that caused error 157C (5500 DEC) = D5500 W228 Record 5 Node Number Function Code 0710 (node 4, function 10) W229 Record 5 DM Area that caused error 1838 (6200 DEC) = D6200 There is also a complete copy of the Modbus string sent out the port, and received back in the port for the last Modbus error. This is for CP1H / CP1L Only. For CJ1 / CJ2 / CS1, use the Data Trace function in CX Protocol to analyze the Modbus strings. W230 W239 = Last sent Modbus Command that caused an error. W240 W249 = Last received Modbus command that contained an error. The current polling cycle time can be viewed in W216 as xx.xx seconds as a BCD data type. Example: W216 = 0140 means is takes 1.40 seconds to scan all the items in the read tables. The CP1H / CP1L PLCs scan 10 items in ~ 0.40 seconds (at 19,200 bps). The CJ1 / CJ2 / CS1 PLCs scan 10 items in ~ 1.30 seconds (at 19,200 bps). The difference in these times is due to the overhead associated with Protocol Macros.

11 Section 7. Data Layout by Function Note: For function code 3 or 4, when reading a single 2 register parameter (such as Accel in a 3G3JX), the result is word swapped.

12 Note: For function code 10, when writing a single 2 register parameter (such as Accel in a 3G3JX), the data needs to be presented in a word swapped format.

13 Section 8. Table Setup Example for 3G3JX Inverter Read Item 1 = Read All Status Coils from node 1 Read Item 2 = Read Frequency and Current from Node 1 Address Value Notes Address Value Notes D Node 1 D Node 1 D Function code 1 D Function code 3 D Start at Coil 0 D Frequency Register D Read 25 Coils (19 HEX) D Read 2 Registers D Coil status D Frequency Returned Here D Coil status D Current Returned Here D Not Used D Not Used D Not Used D Not Used D Data is valid D Data is valid D Not last item D5019 F000 Last Item Write Item 1 = Control Run / Stop and FWD / REV to Node 1 Write Item 2 = Write Frequency to Node 1 Write Item 3 = Reset Inverter Alarm to Node 1 Address Value Notes Address Value Notes D Node 1 D Node 1 D F Function code F D Function code 10 D Start Coil 0 D F Ref Register D Write 2 Coils D Write 1 Register D6004 xx :Run, 0000 :Stop D6014 xxxx Frequency D Not used D Not used D Program controlled D Program controlled D Program controlled D Program controlled D Last Write Successful? D Last Write Successful? D A Not last item, detect same write value Address Value Notes D Node 1 D Function code 5 D Reset Alarm Coil D Write 1 Coil D6024 xx00 FF00 :Reset D Not used D Program controlled D Program controlled D Last Write Successful? D6029 F00A Last Item, detect same write value D A Not last item, detect same write value

14 Appendix A: 3G3JX Inverter Setup (provided as reference material) 1. Connect the PLC to the inverter as shown 2. Initialize the Inverter (to erase any previous settings) as follows: a. Unplug the inverter. b. Verify that S7 is set for OPE. Leave S8 in the Off position. c. Plug in the inverter and wait ~ 30 seconds in case the inverter is set to use Modbus for communications. This lets it timeout. d. Set B84 to 01. e. Press and hold the Mode and Decrement Keys simultaneously. f. Press and Hold the Stop/Reset key until the display blinks. g. Release all 3 keys and let the inverter go through its initialization.

15 3. Change the following Inverter Parameters using the Operator Keypad. a. A001 = 03. Set Modbus as Frequency Reference Input b. A002 = 03. Set Modbus as the Run/ Stop command reference c. C070 = 03. Set Modbus as the input method (not keypad). d. C071 = 06. Set 19,200 as the baud rate 4. Unplug the inverter after making these changes. 5. Set DIP S7 to 485. Leave S8 in the Off position. 6. Plug in the inverter.

16 Appendix B: 3G3JX Coil Numbers When starting at Coil 1 (set in the read item as 0 by Modbus) for a read or write, the coil numbers are as follows for a 3G3JX. This example uses Read Item 1 (D5000) as the item for reading the coils. Shaded = Read only Coil 9 Multi Function Input Coil 10 Multi Function Input Coil 11 Multi Function Input Coil 12 Not Used Coil 13 Not Used Coil 14 Operation Status Coil 15 Rotation Direction Coil 16 Inverter Ready Coil 1 Run Commands Coil 2 Rotation Direction Command Coil 3 External Trip (EXT) Coil 4 Trip Reset (RS) Coil 5 Not Used Coil 6 Not Used Coil 7 Multi Function Input Coil 8 Multi Function Input Coil 25 Signal During Run Coil 26 Not Used Coil 27 Data Writing Coil 28 CRC Error Coil 29 Overrun Error Coil 30 Framing Error Coil 31 Parity Error Coil 32 Checksum Error Coil 17 Not Used Coil 18 Not Used Coil 19 Not Used Coil 20 Alarm Signal Coil 21 Excessive PID Deviation Signal Coil 22 Overload Warning Coil 23 Frequency Arrival Signal (Over Set Frequency) Coil 24 Frequency Arrival Signal (Constant Speed)

17 Revision History Date Notes Version 6/8/2009 Original Document /11/2009 Added CJ1/CS1/CJ Added Memory Layout for Functions Corrected Error in 3G3JX Memory Example 6/18/2009 Changed PMCR timeout to 300 ms from 1 sec Added No Read Items option 2.05